Modelling a high-mass red giant observed by CoRoT
Modelling a high-mass red giant observed by CoRoT
复制标题
对 CoRoT 观测到的大质量红巨星进行建模
DOI：
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
C. Català
中科院分区：
文献类型：
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作者：
F. Baudin;C. Barban;M. Goupil;R. Samadi;Y. Lebreton;H. Bruntt;T. Morel;L. Lefèvre;E. Michel;B. Mosser;F. Carrier;J. Ridder;A. Hatzes;S. Hekker;T. Kallinger;M. Auvergne;A. Baglin;C. Català
G6巨行星HR\，2582 （HD\,50890）被CoRoT观测了大约55天。模式频率是从观测到的光曲线的傅立叶谱中提取出来的。然后计算数值恒星模型，通过与观测条件的比较来确定恒星的特征（质量、年龄等）。我们提供了类似太阳的低频振荡存在的证据，在10到20，$\mu$ Hz之间，在连续的径向顺序之间有$(1.7\pm0.1)\mu$ Hz的规则间隔。只有径向模式清晰可见。从与观测约束相容的模型中，我们发现HR\，2582 （HD\,50890）是一颗质量在（3- \,5\,$M_{\odot}$）范围内的大质量恒星，明显高于红团。它以相当低的径向阶（$n$ = 5\，—\,12）模态振荡。它的演化阶段不能精确地确定：这颗恒星可能在上升的红巨星分支上（氢壳燃烧），年龄大约为155迈珥，或者处于后期阶段（氦燃烧）。为了获得合理的氦量，恒星的金属丰度必须相当低于太阳。我们得到的最佳模型的混合长度明显小于具有相同物理描述的太阳模型（超调除外）。在主层序阶段，堆芯超调量是温和的，约为0.1\,$H_{\rm p}$。
The G6 giant HR\,2582 (HD\,50890) was observed by CoRoT for approximately 55 days. Mode frequencies are extracted from the observed Fourier spectrum of the light curve. Numerical stellar models are then computed to determine the characteristics of the star (mass, age, etc...) from the comparison with observational constraints. We provide evidence for the presence of solar-like oscillations at low frequency, between 10 and 20\,$\mu$Hz, with a regular spacing of $(1.7\pm0.1)\mu$Hz between consecutive radial orders. Only radial modes are clearly visible. From the models compatible with the observational constraints used here, We find that HR\,2582 (HD\,50890) is a massive star with a mass in the range (3--\,5\,$M_{\odot}$), clearly above the red clump. It oscillates with rather low radial order ($n$ = 5\,--\,12) modes. Its evolutionary stage cannot be determined with precision: the star could be on the ascending red giant branch (hydrogen shell burning) with an age of approximately 155 Myr or in a later phase (helium burning). In order to obtain a reasonable helium amount, the metallicity of the star must be quite subsolar. Our best models are obtained with a mixing length significantly smaller than that obtained for the Sun with the same physical description (except overshoot). The amount of core overshoot during the main-sequence phase is found to be mild, of the order of 0.1\,$H_{\rm p}$.
低光度红巨星中的类太阳振荡：开普勒的第一个结果
DOI：
10.1088/2041-8205/713/2/l176
发表时间：
2010
期刊：
The Astrophysical Journal
影响因子：
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作者：
Bedding T
通讯作者：
Bedding T